Hardware Switch no display, no current (0A), no short

xfreaks

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Hello good afternoon.

So i've got a switch that won't turn on, the symptom is No display, nothing short, only draw 0.4A
I've done a few things such as ;
1. Replacing Battery (still no display), holding power button for 15sec but no response
2. The switch did detected in TegraRCM but the switch is patched version one so i can't try the payload method
3. Check all caps around the IC M92T36, BQ24193, and P13USB but no short detected
4. Fuse and Coil is good (there's continuity)
5. I lost a tiny cap above the charging port between the 2 regulator
6. In desperate attempt i tried to replace M92T36 with a new one but it end up make the current fall to 0A
7. I notice there's a shorting cap on the left +MAX 77621AEWI (Between 2 inductor)
8. Remove the crystal/oscillator in +MAX 77621AEWI area

My Question is :
1. Did you guys ever encounter this kind of case?
2. Is there any way to revive this?
3. On point 5, does the tiny caps affect the switch? (Yellow box with arrow) *Switch Front.jpg
4. On point 6, does my new M92T36 is a defect one?, cause if i change it back to the older IC it back to drawing 0.4a
5. Can anyone confirm the shorting cap on point 7 because it have low resistance or it never been short in the first place? (White box with arrow) *Switch Behind.jpg

Switch Behind.jpg *Switch Behind

Switch Front.jpg *Switch Front
 

Alfixes

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Probably few months late but have you checked capacitor on the back close to p13 ic that is often shorted because ic goes bad. Also there shouldn't be any shorts. Maxx77621 also can be reflowed or need changing. Why take oscillator off? Usually they don't go bad.
 

SheriffBuck

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I've had quite a bit of success recently with replacing the battery fuel gauge IC [MAX 17050] on a few boards which were exhibiting the 0.4A power drain, but no screen or shorts etc.

If you can get back to the point where it is drawing 0.4A, then I'd recommend replacing this. Often you'll see that a failed one is chipped or cracked.

Good luck!
 
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